<?php
/**
 * Created by PhpStorm.
 * User: hao
 * Date: 2018/10/29
 * Time: 3:00 PM
 */

namespace app\api\service;


use app\lib\enum\ScopeEnum;
use app\lib\exception\WeChatException;
use think\Exception;
use app\api\model\User as UserModel;

class UserToken extends Token
{
    protected $code;
    protected $wxAppID;
    protected $wxAppSecret;
    protected $wxLoginUrl;

    function __construct($code)
    {
        $this->code = $code;
        var_dump($code);
        $this->wxAppID = config('wx.app_id');
        $this->wxAppSecret = config('wx.app_secret');
        $this->wxLoginUrl = sprintf(config('wx.login_url'),$this->wxAppID,$this->wxAppSecret,$this->code);
    }

    public function get() {
         $result = curl_get($this->wxLoginUrl);
         $wxResult = json_decode($result,true);
         if (empty($wxResult)) {
             throw new Exception('获得session_key及openID时异常，微信内部错误');
         }else {
             $loginFail = array_key_exists('errcode',$wxResult);
             if ($loginFail) {
                $this->processLoginError($wxResult);
             }else {
                return $this->grantToken($wxResult);
             }
         }
    }

    private function grantToken($wxResult){
        //拿到openid
        //数据库里查看，是否有openid
        //如果存在不处理，如果不存在就新增
        //生成令牌，准备缓存数据，写入缓存
        //吧令牌返回到客户端
        //key: 令牌
        //value: wxResult,uid,scope
        $openid = $wxResult['openid'];
        $user = UserModel::getByOpenID($openid);
        if ($user){
            $uid = $user->id;
        }else {
            $uid = $this->newUser($openid);
        }
        $cachedValue = $this->prepareCachedValue($wxResult,$uid);
        $token = $this->saveToCache($cachedValue);
        return $token;
    }

    private function saveToCache($cacheValue) {
        $key = self::generateToken();
        $value = json_encode($cacheValue);
        $expire_in = config('setting.token_expire_in');

        $request = cache($key,$value,$expire_in);
        if (!$request) {
            throw new TokenException([
                'msg' => '服务器缓存异常',
                'errorCode' => 10005
            ]);
        }
        return $key;
    }

    private function prepareCachedValue($wxResult,$uid) {
        $cacheValue = $wxResult;
        $cacheValue['uid'] = $uid;
        $cacheValue['scope'] = ScopeEnum::User;//32为管理员
        return $cacheValue;
    }

    private function newUser($openid) {
        $user = UserModel::create([
            'openid' => $openid
            ]);
        return $user->id;
    }

    private function processLoginError($wxResult) {
        throw new WeChatException([
            'msg' => $wxResult['errmsg'],
            'errorCpde' => $wxResult['errcode']
        ]);
    }
}